Ocean

In a sense, there is only one ocean covering 72% of the planet. One planet, one ocean. That said five oceanic divisions are usually reckoned: Pacific, Atlantic, Indian, Arctic, and Southern; the last two listed are sometimes consolidated into the first three. What's most important to note is that more than 95% of the underwater world remains unexplored.

Recommended Listening

Ocean of Life: How our Seas are Changing - In the David Thomas Conservation Oration, marine conservationist Callum Roberts covers noise pollution, global warming, coral reefs, predatory crabs moving into the Antarctic, dead zones and vampire squids from hell! Key to Roberts' strategies for protection of oceans is the establishment of a network of protected marine zones. He suggests closing 30% of the oceans to control over fishing. The world wouldn’t go hungry and fish stocks would be replenished. "Our prediction for sea food began in South Africa."

Ocean Acidification - The ocean absorbs approximately 26% of the CO2 added to the atmosphere from human activities each year, greatly reducing the impact of this greenhouse gas on the climate. When CO2 dissolves in seawater, carbonic acid is formed. It is this chemical reaction that leads to ocean acidification. Ocean acidity has increased by 30% since the beginning of the Industrial Revolution.